The broad objective of this proposal is to quantitatively evaluate in dynamic terms the intrinsic propulsive performance of intestinal regions of cats and guinea-pigs and to examine how this performance is controlled by interactions among the neural and myogenic subsystems intrinsic to the intestine and the fluid load being propelled. The areas of particular interest are: a) fluid propelling capability under input-output conditions having neglibible resistance and constant capacitance, b) fluid propelling capability under input-output conditions requiring neglible compressional work, c) contribution of specific, intrinsic neural elements to propulsive performance, and d) motility patterns associated with specific types of propulsive performance. The general method of approach will be to measure, in vitro, the amount of fluid propelled from the oral and aboral ends of an intestinal segment into an attached propulsion evaluation system which imposes on the segment well-defined, input-output conditions and permits the amount of propulsive work done in propelling a given fluid volume to be determined. Electrical and contractile activity of intestinal segments will be measured during the evaluation of propulsive performance.